Is niacin safe during pregnancy?

What does the evidence say about niacin during pregnancy?

1. The RDA for niacin during pregnancy is 18 mg of niacin equivalents a day across all reproductive ages, a few mg above the non-pregnant recommendation to support the added energy needs of pregnancy. 1
2. The 18 mg a day pregnancy RDA is higher than the 14 mg a day recommended for non-pregnant women ages 14 to 50, and different again from the 17 mg a day recommended during lactation. 2
3. Modeling combined intake from a standard prenatal supplement plus a typical diet found niacin could approach the World Health Organization's upper intake level, yet flushing, the primary risk of excess niacin, has never been reported in the context of a multiple micronutrient pregnancy supplement, and serious adverse effects require far higher doses. 3
4. Expert bodies don't fully agree on whether pregnancy itself raises niacin needs beyond the extra calories pregnancy requires: Nordic guidance suggests a small additional amount, while a European food safety review found no evidence niacin needs increase beyond what added energy intake already accounts for, aside from specific situations like a multiple pregnancy. 4
5. Significant niacin deficiency causes pellagra, marked by dermatitis, diarrhea, and neuropsychiatric symptoms; good dietary sources include fish, meat, fortified grains and cereals, peanuts, and legumes. 5

Is niacin safe in each trimester?

• First trimester. Niacin needs are the same 18 mg a day target throughout pregnancy, so there's no special first-trimester adjustment. Most prenatal vitamins started in the first trimester already contain enough.
• Second trimester. Requirements stay steady at 18 mg a day. If nausea has made it hard to keep down a prenatal vitamin, food sources like poultry, fish, and fortified grains can help fill the gap.
• Third trimester. The same 18 mg a day target continues. If you're carrying more than one baby, ask your provider whether your individual nutrient needs, including niacin, should be adjusted.

Niacin reference intakes